The Cincinnati Children's Hospital Medical Center (CCHMC), the Virginia Polytechnic Institute and State University (the Virginia Tech), and the LigoCyte Pharmaceuticals Inc. will team together for this application in response to RFA-AI-09-027, entitled Partnerships for Biodefense Food- and Water-borne Diseases (R01). We propose to develop a vaccine against noroviruses (NVs), one of the NIAID Category B food- and water-borne priority pathogens, based on our newly discovered subviral particle, the P particle, of NVs. This P particle is spontaneously formed by 24 copies of the protrusion (P) domain of the viral capsid protein, in octahedral symmetry, with an authentic host receptor binding property, highly immunogenic, easily to produce in E. coli and yeast with extremely high yields and simple procedures for purification, and highly stable under a wide range of physic-chemical conditions, making it an excellent subunit vaccine for mucosal immunization. Four projects representing different early-to-middle product development stages will be performed to evaluate the P particle vaccine. In stage 1 we will perform in vitro and mouse immunization studies and compare different vaccination regimens of P particles by different routes with/without an adjuvant for a maximal safety and efficacy. We also will perform similar studies for proof-of-concept of the usefulness of P particle vaccine using the cell culture model of a newly discovered monkey calicivirus, the Tulane virus. In stage 2 we will characterize the antigenic variations of NVs representing different genotypes of NVs for developing a broadly reactive vaccine based on defined antigenic types (serotypes) with a cocktail or consensus vaccine approach. We also will perform genetic and antigenic analysis of the currently dominant GII-4 viruses to address a question about epochal evolution of NVs for future vaccine strategy against NVs. In stage 3 we will further characterize the safety, immunogenicity and broadness of the candidate vaccine in protection against various NVs using the gnotobiotic (Gn) pig challenge model of human NVs developed in our laboratories recently. In the last stage we will develop a fermentation bioreactor for scale up production of P particles for future evaluation of the vaccine by human volunteer challenge studies and clinical trials. NVs are genetically diverse and there is no suitable cell culture for NVs. Our cocktail/consensus vaccine approach and the procedures for evaluation of the vaccine by the surrogate neutralization assay and using the newly discovered Tulane virus and the Gn pig model are highly innovative. We are confident that a panel of lead candidates (vaccine strains) will be selected ready for future clinical trials by the conclusion of the studies in this application. Narrative/Relevance: Noroviruses (NVs) are an important cause of acute gastroenteritis, affecting people of all ages, in both developed and developing countries. The wide spread nature of NVs due to the low infection dose and the high stability and resistance to disinfectants makes NVs an easy agent for bioterrorist attack. In this study we propose to develop a vaccine against NVs based on our newly discovered subviral particle, the P particle, of NVs. This P particle is spontaneously formed by 24 copies of the protrusion (P) domain of the viral capsid protein, with an authentic host receptor binding property, highly immunogenic, ease to produce in E. coli and yeast with extremely high yields and simple procedures for purification. It is highly stable under a wide range of physic-chemical conditions making it an excellent subunit vaccine for mucosal immunization. NVs have been known to cause a brief protective immunity following a natural infection. In this study we will perform mouse immunization studies with different vaccination regimens and immunization routes of the P particle vaccine for the maximal efficacy and safety. NVs are also genetically diverse but our recent data showed that the receptor binding interfaces of NVs are highly conserved due to a convergent evolution selected by the human histo-blood group antigens. We will perform antigenic characterization of NVs representing different genotypes to design a cocktail/consensus vaccine based on defined antigenic types (serotypes) using a surrogate neutralization assay (receptor blocking assay). NVs remain difficult to cultivate in vitro. We will take advantage of the cell culture system of our newly discovered rhesus monkey calicivirus, the Tulane virus, and the gnotobiotic (Gn) pig model of human NVs to prove concept and to further evaluate usefulness of the vaccine for future development in clinical trials. This project will be conducted by a research team with multidiscipline experts in molecular virology, immunology, vaccine development at the Cincinnati Children's Hospital Medical Center (CCHMC), the Virginia Polytechnic Institute and State University (Virginia Tech) and the LigoCyte Pharmaceuticals Inc. Our highly innovative approach of the unique P particles and the cocktail/consensus vaccine and the novel procedures for evaluation of the vaccine by the surrogate neutralization assay and using the newly discovered Tulane virus and the Gn pig model warrant that we will make a rapid progress leading to the next level of evaluation by the phase I clinical trials toward future commercialization.